Gamma-hydroxybutyrate (GHB) is an endogenous substance found in the brain in mu/mol amounts and also a drug with well-documented misuse in humans. Since GHB became a Schedule I compound in 2000, the abuse liability of GHB precursors gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) have begun to receive more attention. There have been few investigations into the reinforcing properties of GHB, GBL, and 1,4-BD, and the results have been inconsistent. Because GHB, GBL, and 1,4-BD have some sedative effects, the amount of time subjects have access to GHB, GBL, or 1,4-BD for self-injection may play a pivotal role when measuring the reinforcing effectiveness of these drugs. Thus, the current proposal will examine the reinforcing properties and abuse liability of GHB, GBL, and 1,4-BD in baboons using a 24 hr IV self-administration procedure. The behavioral effects of self-administered GHB, GBL, and 1,4-BD on food-maintained responding, spontaneous behaviors, and a fine motor task will also be characterized. The results of the proposed study will characterize the abuse liability of GHB, GBL, and 1,4-BD by use of a well-established method of abuse liability testing in non-human primates.